1. Field of the Invention
The present invention relates to an active matrix display device and driving method thereof.
2. Description of the Related Art
In an active matrix display device, switching elements and display elements are provided in hundreds of thousands to several millions of pixels arranged in matrix. Since application of voltage or supply of current is kept for a while by the switching elements after a video signal is inputted to a pixel, active matrix display device can respond flexibly to enlargement of display panels and high definition of display image; thus, active matrix display device is becoming mainstream.
A typical driver circuit of the above display device includes a scan line driver circuit and a signal line driver circuit. By the scan line driver circuit, a plurality of pixels are selected per one line or per a plurality of lines in some cases. Then, by the signal line driver circuit, input of a video signal to the pixel included in the selected line is controlled.
In the case of a display device using a liquid crystal material for a display element, AC drive in which polarity of the voltage applied to the display element is reversed in accordance with give timing in order to prevent deterioration of the liquid crystal material called image burn-in. For example, reference 1 (Japanese Patent No. 3481349) discloses voltage should be applied to the liquid crystal layer by AC drive. Specifically, AC drive can be performed in such a way that the polarity of a video signal inputted to each pixel is reversed based on common voltage as a reference.